We propose to develop a nanopore composite using the biopolymer chitosan that can deliver drugs capable of treating peptic ulcers caused by Helicobacter pylori (H. pylori). Although H. pylori is susceptible to many antimicrobial agents in culture, clinical trials with one single antimicrobial agent have often proven to be unsuccessful. The reasons included degradation of the anti-microbial agent (e.g. amoxicillin and clarithromycin) by gastric acid and the short residence time of the agent in the stomach. We intend to develop a chitosan drug delivery system that will adhere to stomach mucosurface and deliver antibiotics closer to sites infected by H. Pylori. [unreadable] [unreadable] The novel drug delivery system is expected to accomplish: (1) An interpenetrating network of silica and chitosan that prevents chitosan's leaching into acid and controls drug's release rate in stomach; (2) Strong adhesion (by chitosan's cationic amino groups at acidic condition) to the gastric mucosal surface that prolongs and enhances drug's delivery near bacteria colonies; (3) Engineered pore structure (through morphology control at nanometer scale) that maximizes drug's antibacterial performance by regulating its release rates; (4) A dense layer of ligand groups on silica pore surface with a designed function in facilitating a drug delivery. [unreadable] [unreadable]